Oil removing device for refrigerator evaporators



R. H. MONEY Oct. 23, 1934.

OIL REMOVING DEVICE FOR REFRIGERATOR EVAPORATORS Filed June 15, 1935 IN VENTO ATTORNEYfi Patented Oct. 23, 1934 UNITED STATES OIL REMOVING DEVICE FOR- REFRIG- ERATOR EVAPORATORS Roland H. Money, Cincinnati, Ohio, assignor to The Crosley Radio Corporation, Cincinnati,

Ohio, a corporation of Ohio Application June 13, 1933, Serial No. 675,570

9 Claims.

The operation of the usual electric refrigerator results in the entrainment of oil from the compressor in the refrigerant. This oil is usually formed into a mist in the crank case, and passes into the refrigerant, and with it, through the condenser and into the evaporator. The refrigerant is removed from the evaporator, not in the form of a liquid, but in the form of a gas, as a consequenceof which there is no such force acting to w remove the oil from the evaporator, as there is to carry the oil through the condenser. Devices have been provided to maintain the liquid level of the refrigerant in the evaporator, as a consequence of which some of the oil may enter the pipe leading to the compressor; but this oil is usually in the-form of discrete particles, which have a tendency to return down the pipe and re-enter the evaporator. Such coalescence as occurs between particles merely increases this tendency. As a consequence of this, oil tends to collect in the evaporator at the expense of the other parts of the refrigerating system. This discussion of course has the initial premise that the refrigerant used is one of a type with which the oil is not miscible. An example of such a refrigerant issulphur dioxide.

I have discovered that it is possible to remove oil from the evaporator and carry it back into the other parts of the system; and the primary object of my invention is the provision of means for accomplishing this end. Ancillary objects of my invention relate to the provision of improved structures for the accomplishment of my main object; and the several objects of my invention will be apparent to one skilled in the art upon reading these specifications, wherein I have set forth', certain exemplary embodiments of my invention.

Reference is now made to the drawing which 40 forms a part hereof, and in which Figure 1 is a view showing in elevation an exemplary evaporator with certain parts in section, and showing also one embodiment of my invention.

Fig. 2 is a different embodiment of my invention.

Fig. 3 shows a modification of the structure of Fig. 2 to give it certain additional utility, as will hereinafter be explained.

Briefly, in the practice of my invention I pro- 0 vide means for permitting the oil entrained in, or floating upon, the refrigerant to collect in a withdrawal device, and to leave the oil so collected substantially undisturbed until, by the amalgamation of the particles of the oil, a sufficient body thereof is produced so that this body will be driven by the force of the gas withdrawn from the evaporator through the pipes and back to the compressor. I provide means for insuring the collection of a sufiicient body of oil prior to its being drawn up into the pipes. I have discovered that if a sufficient body of oil is so collected, and then is suddenly caused to be acted upon by the gas, that it will be drawn through the device and fittings as an integral, unitary body, or slug, and will succeed in reaching the compressor even when the compressor is located above the evaporator. H

To this end, in my several constructions I provide a sump in which the oil may collect, together with means whereby the collecting oil does not close off the gas passageway until there is a sufiicient body of it to close off the passageway completely, and to proceed as a unit driven by the gas through the piping.

In Fig. 1, I have shown at 1 an evaporator which may. be of any desired type. The particular evaporator shown is the evaporator of my copending application for Letters Patent, Ser. No. 675.571, filed June 13, 1933. In this particular type, which will be understood as forming no limitation upon my invention, the refrigerant enters thebottom of the device, through a capillary tube 2 and a fitting 3. It proceeds up and around the sides of the evaporator, and partially fills a chamber 4 at the top thereof. The gas formed by the evaporation of the refrigerant is withdrawn through a fitting 5, to which the return piping to the compressor is attached. In Fig. 1, I have shown a skimmer arrangement comprising a pipe 6, attached to the fitting 5, and through which the evaporated refrigerant is drawn. This pipe 7 has an open end at "I, which serves to determine the level of the liquid refrigerant in the evaporator, assuming that the flow of refrigerant to the evaporator is suitably controlled. The skimmer is, however, characterized by a downwardly extending portion 8, and an upwardly extending portion 9 formed by reversely bending the tube 6. The upwardly and downwardly extending portions provide, as will be clear, a sump portion 10 which is lower than both the entrance 7 and the straight portion 6 of the tube. The level of the lower refrigerant is indicated at 11, and will, as aforesaid, be determined by the position of the entrance portion 7 of the skimmer 2. Oil entering this tube, with the gas or liquid, collects in a pool 12 in the sump portion, and remains there, the gas passing above it and returning to the compressor. As additional oil enters the tube 6, it amalgamates with the oil 12 in the sump so that this body of oil becomes larger. With the continued collection of oil, a point is reached at which the body 12 closes off the sump, and at this point the action of the gas is to propel the body of oil 12 as a unitary slug through the swimmer and fitting 5, and up through the piping to the compressor. The body of the oil is large enough and cohesive enough to act as a unit, and it will travel as such throughout the piping. It is necessary that the oil collect in a body of sufiicient volume to close oif completely a cross section of the pipe. If provision is not made for this, the gas will pass the body of oil and will not propel it. The oil would under such circumstances fiow down the piping by gravity, and re-enter the evaporator as it does in the ordinary constructions.

I have shown in Fig. 2 a modified construction, of particular utility, where the compressor connection is made into the top of the evaporator. The evaporator wall is indicated at 1a, to which there is attached by welding, or other suitable means, a fitting 13. The compressor piping is indicated at 14, and is held to the fitting 13 by a suitable bushing member 15. The fitting is perforated as at 16 to form a continuation of the tube 14, and the lower part of the fitting is reduced, and extends downwardly as at 17 to form a nipple. A cap 18 is placed over the fitting as shown.

- It is perforated as shown at 19 to admit th refrigerant. These perforations, of course, serve to determine the level of the refrigerant in the evaporator 1a,. and the refrigerant itself'is shown at 11a. It will be seen that the nipple 17 extends down below the level of the perforations 19, and also that the bottom of the cap extends considerably below the end of the nipple so as to form a sump. Oil entering the perforations 19 with the refrigerant, in either gaseous or liquid form, collects, in the sump portion 20 to form a body 21, the gas, however, passing through the nipple. The oil 21 does not contact the end of the nipple until a predetermined body of it has collected. When this happens, the

' oil at once closes ofli the opening of the nipple and is propelled by the gas entering the perforations 19, through the nipple and up the tubing 14 as a unitary body or slug. l

I have shown in Fig. 3 a modification of the structure, Fig. 2, in which like parts have been given like indicia. The fitting in this instance is marked 13a, and it is designed to provide not only the oil removal means, which I have hereinabove described, but also to provide means for suspending the evaporator from a suitable support. To this end the tube 14 enters the fitting from the side and is held by the bushing 15.v The upper end of the fitting is provided with a threaded extension 22, which may be caused to pass through a suitable bracket member 23, and to be held thereto by a nut 24. This construction provides a means for supporting the evaporator within the refrigerator.

I have described certain exemplary embodiments of my invention, but it will be clear that modifications may be made therein, or other embodiments produced by the man skilled in the art without departing from the spirit of my invention, the essential novelty of which I have set forth in the appended claims.

I Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is:-

1. In a withdrawal device for gaseous refrigerant adapted to be placed in an evaporator, a substantially horizontal passageway for gas removal,

a skimming opening and means within said pas sageway, and adjacent said opening providing a space for the collection of non-gaseous material and the retention thereof, by gravity, said means being so proportioned as to permit the collection of a predetermined quantity of non-gaseous material without closing off the passageway for removal of the gas, but so proportioned as to cause said non-gaseous material to close off said means for the removal of gas when more than a predetermined quantity has been so collected.

2. In a skimmer and gas removal device for refrigerating machines, means providing a substantiallyhorizontal passageway for gas removal, a skimming mouth and means for providing a sump adjacent said mouth for the collection of non-gaseous material, said sump being so located within said passageway as to cause said nongaseous material to close off said passageway when more than a predetermined quantity has been so collected.

3. In a device for the purpose described, means for the withdrawal of gas, a skimming mouth and means for the collection of non-gaseous material in a body, said several means comprising a bent tube, and being so proportioned that when more than a predetermined volume of non-gaseous material has been so collected, said nongaseous material will close off said means for gas removal, and will be bodily withdrawn therethrough.

4. In a skimmer, a conduit having an opening in its end only, disposed substantially horizontally throughout a portionat least of its length and bent so as to provide a downwardly depending loop-like portion adjacent said opening forming a sump for the collection of non-gaseous material, said sump being located substantially below the general level of said skimming device, and specifically below said skimming opening.

5. In combination with an evaporator, a skimming device having a substantially horizontally disposed tube located within said evaporator and having a, portion bent downwardly and then upwardly to provide a sump located essentially below the general level of said tube and having an orifice only at the end of the said upwardly bent portion.

6. In combination with an evaporator, a skimming device therein comprising a, tube having a horizontally extending portion, a downwardly extending portion and an upwardly extending portion, said portions being continuous, and said tube being provided with an orifice for the admission of materials only at the end of the said upwardly extending portion, said downwardly and upwardly extending portions forming a sump located generally below but adjacent to said orifice and below said horizontal portion of said tube.

7. In combination with a gas removal device for refrigerating machines, means for the removal of non-volatile materials entrained in the refrigerant, said means comprising a cup-shaped sump, a nozzle extending down into the said sump, and orifices in the walls of the said sump substantially at the level of the liquid refrigerant, but above the orifice of the said nozzle, whereby the said non-volatile materials are skimmed from the surface of the liquid refrigerant, and are permitted to collect in the sump until a predetermined quantity of such materials has collected therein, at which point the orifice of the nozzle 8. In combination with a gas removal device for refrigerating machines, means for the removal of non-volatile materials entrained in the liquid refrigerant, said means comprising a fitting perforated for the removal of gas and terminating in a nozzle shaped portion, a cup-shaped member surrounding said nozzle-shaped portion to form a sump, portions of the side walls of said cup-shaped member extending above the entrance to said nozzle-shaped portion, and spaced therefrom, said side walls having perforations for the ingress of materials, said perforations lying essentially above the entrance of said nozzleshaped portion, and substantially at the level of the liquid refrigerant, whereby said non-volatile materials are skimmed from the surface of the liquid refrigerant and are permitted to collect in the said sump until a suflicient quantity thereof has collected to block off the entrance to the said nozzle, whereupon the said materials are forced bodily through the said nozzle by the pressure of the gaseous refrigerant.

9. In combination with an evaporator of the flooded type, a skimming device located therein and having a skimming orifice located at the liquid level of refrigerant in said evaporator, having withdrawal means for gaseous refrigerant associated with said skimming orifice, and having means in operative connection with said aforementioned means for the collection of lubricant, said last mentioned means being of a size to permit the collection of a quantity of lubricant large enough to pass as a body through said'withdrawal means before closing off said withdrawal means.

ROLAND H. MONEY. 

